Image forming apparatus, control method and non-temporary recording medium

Abstract

In accordance with an embodiment, an image forming apparatus, comprises an image forming section configured to include at least one decolorable toner and at least one non-decolorable toner, and form a toner image selectively using the decolorable toner and the non-decolorable toner; a mode determination section configured to determine, from a plurality of image forming modes including a first image forming mode in which a toner image is formed on a sheet with one decolorable toner and a second image forming mode in which a toner image is formed on a sheet with two or more toners of the decolorable toner and the non-decolorable toner, a designated image forming mode; and a preheating control section configured to execute the preheating of the sheet before image formation in the second image forming mode, and execute no preheating of the sheet before image formation in the first image forming mode.

What is claimed is: 
     
       1. An image forming apparatus which forms an image according to an image forming mode, comprising:
 an image forming section configured to include at least one decolorable toner and at least one non-decolorable toner, and form a toner image selectively using the decolorable toner and the non-decolorable toner; 
 a transfer section configured to transfer the toner image formed by the image forming section to a sheet; 
 a fixing section configured to fix the toner image on the sheet by heating and pressing the toner image; 
 a fixing control section configured to control a set temperature of the fixing section; 
 a mode determination section configured to determine, from a plurality of image forming modes including a first image forming mode in which a toner image is formed on a sheet with one decolorable toner and a second image forming mode in which a toner image is formed on a sheet with two or more toners of the decolorable toner and the non-decolorable toner, a designated image forming mode; and 
 a preheating control section configured to execute preheating of the sheet before image formation in the second image forming mode, and execute no preheating of the sheet before image formation in the first image forming mode. 
 
     
     
       2. The image forming apparatus according to  claim 1 , wherein
 the preheating control section preheats the sheet with the fixing section. 
 
     
     
       3. The image forming apparatus according to  claim 2 , wherein
 the preheating control section preheats the sheet before a toner image is transferred to the sheet by the transfer section. 
 
     
     
       4. The image forming apparatus according to  claim 3 , wherein
 the preheating control section conveys the sheet preheated by the fixing section to the transfer section; and 
 the transfer section transfers a toner image to the preheated sheet. 
 
     
     
       5. The image forming apparatus according to  claim 4 , wherein
 the fixing control section fixes the toner at a set temperature lower than a set temperature in the first image forming mode on the preheated sheet. 
 
     
     
       6. The image forming apparatus according to  claim 5 , wherein
 the preheating control section controls a set temperature in the second image forming mode to a temperature within a given range from the set temperature in the first image forming mode. 
 
     
     
       7. The image forming apparatus according to  claim 6 , wherein
 the mode determination section determines an image forming mode to be the first image forming mode in the case in which the printing using only decolorable toner is not a color printing. 
 
     
     
       8. The image forming apparatus according to  claim 7 , wherein
 the preheating control section controls the conveyance speed of the sheet such that the preheated sheet arrives at the transfer section at a specific temperature. 
 
     
     
       9. A control method carried out by an image forming apparatus which forms an image according to an image forming mode, including:
 including at least one decolorable toner and at least one non-decolorable toner, and forming a toner image selectively using the decolorable toner and the non-decolorable toner; 
 transferring the formed toner image to a sheet; 
 fixing the toner image on the sheet by heating and pressing the toner image; 
 controlling a set temperature of the fixing section; 
 determining, from a plurality of image forming modes including a first image forming mode in which a toner image is formed on a sheet with one decolorable toner and a second image forming mode in which a toner image is formed on a sheet with two or more toners of the decolorable toner and the non-decolorable toner, a designated image forming mode; and 
 executing preheating of the sheet before image formation in the second image forming mode while executing no preheating of the sheet before image formation in the first image forming mode.